standard atmosphere

[tompouce]

Am currently working on performance predictions for helicopters but I lack some data on atmosphere.

I read somewhere that specific models existed for cold regions and hot ones. I've been googling for it and haven't found much except than saying such charts exist with no links. I've also searched the NASA/NACA database for these charts but haven't found anything.
Does anyone have a link to these charts or know where I could find specific information?

I remember reading that the ISA chart isn't correct for such different climates.

thanks in advance
tom

the difference between a kid's passion and an mine is that I'm going to get paid for it.

 

[davidjh]

I also have a vague memory of such a chart. Perhaps a search of ICAO documents , or the NATO AGARD committee documents.

Good Luck

 

[WKTaylor]

Check out SAE AIR 1168/9 "Thermophysical Properties of the Natural Environment, Gases, Liquids, and Solids".

Regards, WKT

Regards, Wil Taylor

 

[davidjh]

The old P&W vest pocket handbook (mine - 1978 version)has such a chart. It defines a hot, tropical, cold and polar atmosphere each with their unique "non-standard" lapse rates. The handbook references a MIL-STD-210A.

 

[IRstuff]

The replacement for MIL-STD-210 is MIL-HDBK-310, but I don't recall either have lapse rate tables.

TTFN

 

[davidjh]

Have just become aware of a NASA-HDBK-1001 which is a definition of the earth's environment. Do not know its precise content, but know it does talk to atmospheric temperatures, so appears to be relevant to your question.

 

[IRstuff]

NASA-HDBK-1001 can be downloaded at:

http://standards.nasa.gov/NPTS/public_login.taf

You'll need to register to get in

TTFN